What Are The Operating Skills Of CNC Lathes?

Currently, CNC machine operators can be divided into two parts. One part is very familiar with mechanical processing, but is relatively unfamiliar with CNC machine programming; the other part is fresh graduates, who are familiar with mechanical processing knowledge, CNC processing and programming theory, but lack practical mechanical processing experience; there are also many operators who have never been exposed to mechanical processing and programming, so it is very difficult for them to learn CNC machine operation. Today we share several CNC Lathe machine operation skills with you:

Programming Skills:

Be proficient in program editing, parameter compensation of each process, and compensation of tool or grinding wheel diameter and length.

1. Processing Order Of Parts:

Drill first and then flatten (this is to prevent shrinkage during drilling);

Rough turn first, then fine turn (this is to ensure the accuracy of parts);

Process large tolerance first and small tolerance last (this is to ensure that the surface of small tolerance size is not scratched and prevent parts from deformation).

2. Choose Reasonable Speed, Feed Rate And Cutting Depth According To The Hardness Of The Material:

1) For carbon steel materials, choose high speed, high feed rate and large cutting depth. For example: 1Gr11, choose S1600, F0.2, cutting depth 2mm;

2) For cemented carbide, choose low speed, low feed rate and small cutting depth. For example: GH4033, choose S800, F0.08, cutting depth 0.5mm;

3) For titanium alloy, choose low speed, high feed rate and small cutting depth. For example: Ti6, choose S400, F0.2, cutting depth 0.3mm. Take the processing of a certain part as an example: the material is K414, which is a special hard material. After many tests, S360, F0.1 and cutting depth 0.2 were finally selected to process qualified parts.

Tool Setting Skills:

Tool setting is divided into tool setting instrument tool setting and direct tool setting. First, select the center of the right end face of the part as the tool setting point and set it as the zero point. After the machine tool returns to the origin, each tool that needs to be used is set with the center of the right end face of the part as the zero point; when the tool touches the right end face, enter Z0 and click Measure, and the tool compensation value of the tool will automatically record the measured value, which means that the Z axis tool setting is done. The X tool setting is a trial cut. Use the tool to turn the outer circle of the part less, measure the outer circle value (such as x is 20mm) and enter x20, click Measure, and the tool compensation value will automatically record the measured value. At this time, the x axis is also set; this tool setting method, even if the machine tool is powered off, the tool setting value will not change after the power is turned on and restarted. It can be used for mass production of the same part for a long time, and there is no need to re-set the tool when the lathe is turned off.

Debugging Skills:

After the parts are programmed and the tool is aligned, trial cutting and debugging are required. In order to prevent errors in the program and tool alignment, which may cause collision accidents, we should first simulate the empty stroke, and move the tool to the right by 2-3 times the total length of the part in the coordinate system of the machine tool; then start the simulation processing. After the simulation processing is completed, confirm that the program and tool alignment are correct, and then start processing the parts. After the first part is processed, self-check it first, confirm that it is qualified, and then find a full-time inspection. After the full-time inspection confirms that it is qualified, it means that the debugging is over.

Complete The Processing Of Parts:

The basic principle of parts processing: first rough processing, remove the excess material of the workpiece, and then fine processing; vibration should be avoided during processing; avoid thermal denaturation of the workpiece during processing. There are many reasons for the vibration, which may be excessive load; it may be the resonance of the machine tool and the workpiece, or it may be the lack of rigidity of the machine tool, or it may be caused by the passivation of the tool. We can reduce vibration by the following methods; reduce the lateral feed rate and processing depth, check whether the workpiece is clamped firmly, increase the speed of the tool or reduce the speed to reduce resonance, and check whether it is necessary to replace the new tool.

Prevent Machine Tool Collision:

Machine tool collision is a great damage to the accuracy of the machine tool, and the impact on different types of machine tools is different. Generally speaking, it has a greater impact on machine tools with weak rigidity. Therefore, for high-precision CNC lathes, collisions must be absolutely eliminated. As long as the operator is careful and masters certain anti-collision methods, collisions can be completely prevented and avoided.

The main reasons for collisions:

1. Wrong input of the diameter and length of the tool;

2. Wrong input of the workpiece size and other related geometric dimensions and wrong initial positioning of the workpiece;

3. The machine tool's workpiece coordinate system is set incorrectly, or the machine tool zero point is reset during processing;

4. Most machine tool collisions occur during the rapid movement of the machine tool. The harm of collisions at this time is also the greatest and should be absolutely avoided.

Therefore, the operator should pay special attention to the initial stage of the machine tool in the execution of the program and when the machine tool is changing the tool. At this time, once the program is edited incorrectly, the diameter and length of the tool are entered incorrectly, then it is easy to collide. At the end of the program, the sequence of the CNC axis's tool retraction action is wrong, then a collision may also occur.

In order to avoid the above collisions, the operator should give full play to the functions of the five senses when operating the machine tool, and observe whether the machine tool has abnormal movements, sparks, noise and abnormal sounds, vibrations, and burnt smells. If an abnormal situation is found, the program should be stopped immediately, and the machine tool can continue to work after the machine tool problem is solved.

In short, mastering the operation skills of CNC machine tools is a gradual process and cannot be achieved overnight. It is based on mastering the basic operation of machine tools, basic mechanical processing knowledge and basic programming knowledge. The operation skills of CNC machine tools are not static. It requires the operator to give full play to the organic combination of imagination and hands-on ability, and is innovative labor.